Retort pouch is a packaging pouch with several layers, which makes it different from other packaging types. The outer layer is made up of polyester, aluminium layer in the middle, and polypropylene layer in the inner part. This pouch is used to store food items with low acidity to maintain their shelf life by providing them with strong barrier against the external environment.
Source: https://www.bharatbook.com/report/1372594/global-retort-pouches-market-report-and-forecast